Have you ever overheard a conversation where someone was talking like they knew what they were talking about, but you know they were completely wrong? The "facts" make it sound plausible, but ultimately the reasoning is incorrect. For example, if someone said that motorcycles are so fast because their cross section was so much smaller than a car. "Gee golly, why look at it. It's so tiny that it hardly has any air to push out of the way." That's what this reminds me of.
It may work, but all they have is speculation. Unfortunately, they present their case with a lot of emotion and wildly uncontrolled evidence gathering. This only reduces their credibility. Notice in the "Introduction to Groove Theory" page, they have Before and After pictures of a cylinder head. The After picture shows that the head has been milled, quite a bit actually. It's possible with even the grooving, they upped the compression slightly. We don't know if they used a compensatory head gasket. Also, it's likely that the head was run less miles than when the Before picture was taken. Certainly, the engine was more carefully attended to between the Before and After periods.
It really makes me wonder if they're stupid... or think i am. Do believe that what they presenting is real proof? Do they think i'd believe it is?
I can make up my own equally plausible speculation... You see it has nothing to do with directing squish gasses at the spark plug or maintaining long mixture swirl. The REAL reason it works is because it's preventing the pressure and suction when two flat surfaces come into close proximity of each other.
It's like when you take two big flat sheets of metal and you squish them together. All that air pressure that builds up slows you down from putting them together. The air in the middle has to rush all the way out to the sides. Suction keeps you from pulling them apart. You have to let the air rush all the way back in the middle.
What the grooves REALLY do is make a closer "edge" for air to escape to. The air only has to travel a short distance to and from the channel instead of across a wide flat area. This reduces pressure AND suction. That's TWO TIMES as efficient! 8)
As the piston gets close to TDC, the flat top of the piston and flat area of the head start building pressure. Like those two flat sheets, it gets hard to squeeze them together quickly. Like a brake, this causes the piston to slow down. Then when the piston comes back down, the suction makes it slow down even more! It's amazing engines run at all, but the car companies don't want to make them efficient so you'll buy more gas.
So now you know the real reason it works. It prevents pressure and suction from building when the two flat areas are near each other.
Please, don't believe that.
.
